Akamai's "The State of the Internet 4th Quarter, 2012" [here] report finds that the ".. number of Distributed Denial of Service (DDoS) attacks that Akamai saw in 2012 grew significantly from 2011. While 250 attacks were reported in 2011, 2012 saw 768 attacks reported by our customers, a year-over-year increase of more than 200%.
.. over a third (269 or 35%) of the attacks targeted companies in the Commerce sector. An additional 164 attacks (22%) targeted Media and Entertainment companies, followed closely by companies classified as Enterprise, which were targeted by 155 attacks, accounting for 20% of the total. High Tech companies were targeted by 110 attacks (14%), while Public Sector agencies were the target of 70 attacks (9%) last year. The 768 attacks were reported by 413 unique organizations, meaning that many organizations were targeted more than once — some significantly more.
".. attack traffic among the top 10 targeted ports [see chart] increased slightly during the fourth quarter of 2012, with these ports targeted by 60% of observed attacks, up from 59% in the third quarter, but down from the second and first quarters. The percentage of attacks targeting port 445 dropped very slightly quarter-over-quarter, though not as significantly as the declines seen earlier in the year".